You have created a survey and need to make changes. When you edit the survey part you see there are results listed at the bottom of the page and no way to edit the survey questions or add new ones.
A new survey will need to be created to add, remove or correct choices on a survey that has at least 1 submission.
After 1 submission has occured, a survey form cannot be changed. This is to make sure the survey is constent throughout the course of the survey and everyone has the same choices. Changing the data midstream would skew the results of he survey.